PL2.2 Pembrolizumab (PEM) in recurrent high-grade glioma (HGG)patients with mismatch repair deficiency (dMMR): an observational study

BACKGROUND

Pem, an immune checkpoint inhibitor, demonstrated to be activein various neoplasms with MMRd. No data exists about its efficacy in MMRdglioma patients.

MATERIAL AND METHODS

MMRd HGG relapsed after receiving RT and CT weretreated with Pem. MMR status was analyzed by immunohistochemistry,including the MLH1, MSH2, MSH6, and PMS2 markers. MMR deficiency wasdefined as presence of a weak (wMMRd) or absent (aMMRd) signal atimmunohistochemistry for at least one MMR protein. Other inclusion criteriawere: ECOG PS 0–2, histologically confirmed gliomas, dexamethasone ≤4 mg.Pem was administrated at 200 mg every 3 weeks until progression disease orunacceptable toxicity. Tumor response was evaluated by brain MRI every 10 weeksaccording to the RANO criteria. OS and PFS were evaluated by Kaplan-Meiercurves. CTCAE v4.0 was used for toxicity.

RESULTS

among 167 glioma patients, we found 22 MMRd gliomas. 12 PTS were treated with Pem: 8 wMMRd and 4 aMMRd. According to Bethesda criteria, allPTS had microsatellite stability. Tumor histologies included 5 anaplasticastrocytoma, 1 anaplastic oligodendroglioma, 6 glioblastoma (GBM). MSH2deficiency was found in 6 cases, MSH6 deficiency in 9 cases, PMS2 and MLH1deficiency in 2 cases. Median number of prior line of chemotherapy was 1 (range 1–5). Stable disease (SD) was reported in 4 PTS (33%); 8 PTS showedprogressive disease (PD). PTS with anaplastic gliomas showed a statisticallysignificant association with SD (p=0.03, OR=3); all GBM PTS reported PD; status of MMRd (weak/absent), IDH (mutated/wild-type), MSH2 and MLH6(deficient/proficient) were not associated with SD. Median follow up was 14.7 ms. OS was 5.6 ms (95% CI 0.1–13.8), PFS 2.4 ms (95% CI 1.8–2.9). OS was 2.8 ms and 5.6 ms (p=0.9), PFS was 1.8 ms and 3.1 ms (p=0.5) in PTS with wMMRd and aMMRd. PTS reporting SD and PD had PFS of 7.4 ms (95% CI 4.6–10.2) and 1.8 ms (95% CI 0.2–3.4), p=0.002; OS was “not reached” and 2.8 ms in PTS having SD vs PD (p=0.04). Grade ≥3 adverse eventswere reported in 8% of PTS.

CONCLUSION

a subgroup of recurrent MMRd HGG might benefit from Pem,especially anaplastic gliomas. There was a trend for a longer PFS and OS in PTS with aMMRd. Analyses for identifying additional molecular predictive factors is ongoing.

P05.08 High-grade gliomas and immunotherapeutic early phase clinical trials: a single-center experience

BACKGROUND

Patients with high-grade gliomas (HGGs) have historically been excluded from immunotherapeutic early-phase clinical trials (ieCTs) due to unavailability of serial bioptic sampling, the frequent need of corticosteroids, concerns regarding activity of immunotherapy in central nervous system, and rapid clinical deterioration.

MATERIAL AND METHODS

We retrospectively reviewed data of all recurrent HGG patients enrolled in ieCTs at Humanitas Cancer Center Phase I Unit between 2014 and 2019. Disease control rate (DCR) according to RANO criteria, six-months progression-free and overall survival (PFS-6; OS-6), and treatment-related adverse events (TRAEs), were evaluated. A control-cohort (CC) of patients treated with standard treatments (temozolomide, fotemustine, lomustine and procarbazine, bevacizumab) matched (1:1) for sex, age, line of treatment, MGMT methylation status, and IDH mutational status, was selected for comparison. A series of clinical parameters with an established prognostic value for patients with solid tumors treated into ieCTs were correlated with survivals through an univariate analysis. These include: use of steroids, neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, monocyte-to-lymphocyte ratio, lactate dehydrogenase, albumin, total protein.

RESULTS

Five among the 23 ieCTs conducted at our Phase I Unit allowed inclusion of HGG patients. 25 patients were enrolled in the experimental cohort (EC): 22 (88%) glioblastoma, 3 (12%) anaplastic astrocytoma. Median age was 50 years (range 25–71); 16 patients (64%) were men, 9 (36%) women; 17 pts (68%) required steroid therapy, with a median baseline dexamethasone dose of 2 mg (range 1–6). The median number of prior systemic therapies was 1 (range 1–2). Twelve patients (48%) received monotherapies (anti PD-1, anti CSFR-1, anti TGF-ß, anti cereblon), 13 (52%) combination regimens (anti PD-L1 + anti CD38, anti PD-1 + anti CSFR-1). DCR was 40% (1 CR + 2 PR + 7 SD) and 37% (9 SD), in EC and CC, respectively. Four patients (16%) in EC had grade ≥3 TRAEs (1 neutropenia, 1 pneumonia, 2 hepatitis). With a median follow-up of 14 months PFS-6 were 35% and 16% (p=0.075), in EC and CC respectively, while OS-6 was significantly improved in the EC (82% vs 44%, p=0.004). In our small series, none of clinical factors resulted prognostic.

CONCLUSION

Survival outcomes of ourHGG patients treated into ieCTs compared very favorably with a matched CC. Inclusion of HGGs patients into ieCTs should be strongly encouraged. Identification of clinical factors to select who may benefit from ieCTs still remains crucial.

Laparoscopic lateral ovarian transposition: a fertility sparing procedure

This article reports the case of a 30-year-old woman who, in 2003, had diffuse large B-cell lymphoma of the left vaginal fornix, associated with sclerosis. After six chemoimmunotherapy cycles the patient underwent a laparoscopic procedure for lateral ovarian transposition to spare ovarian function before radiotherapy. Six months after the transposition the evaluation of ovarian function was performed. The hypothalamic-pituitary-ovary axis was normal. Three years after radiation therapy (2006) the patient spontaneously conceived. Her pregnancy proceeded regularly. She had an uneventful vaginal delivery. Lateral ovarian transposition with tubal anatomy preservation, which is an underused technique, can be successfully used to spare ovarian function in women who undergo pelvic radiotherapy and to let them achieve spontaneous pregnancy.

Polyamide microcapsules containing jojoba oil prepared by inter-facial polymerization

Jojoba oil containing polyamide microcapsules having diameter of approximately 5 microm were prepared by inter-facial polycondensation by direct method (oil-in-water). Qualitative effects of both the formulation and the process parameters on microcapsules characteristics were investigated by SEM observations. Morphological analysis showed the dependence of the external membrane compactness on the chemical nature of the water-soluble polyamine and the oil-soluble acid polychloride: 1,6-hexamethylenediamine (HMDA) and terephthaloyl dichloride (TDC) were found to favour the production of smooth and dense surfaces. The use of ultrasonic irradiations during the dispersion step to get a further reduction of microcapsules size was also evaluated.

Efficacy and tolerability of once-daily cephalexin in canine superficial pyoderma: an open controlled study

OBJECTIVES

The aims of this study were to evaluate the efficacy and tolerability of oral cephalexin given at 30 mg/kg once daily in dogs with superficial pyoderma and to compare them with those of oral cephalexin given at 15 mg/kg twice daily.

METHODS

Twenty dogs with superficial pyoderma were treated with cephalexin at 30 to 60 mg/kg orally once daily (group A) and compared with 20 dogs treated at a dose of 15 to 30 mg/kg orally twice daily (group B). Dogs were treated until 14 days after clinical remission. Type and distribution of lesions, pruritus and general health status were assessed every 14 days using a numerical scale until 14 days after treatment discontinuation. Total scores for each evaluation day were compared between the two groups as well as time to obtain resolution and percentage of relapses.

RESULTS

Resolution of superficial pyoderma was obtained in all dogs in 14 to 42 days (median 28 days for both groups), with no difference between groups. Six dogs experienced vomiting or diarrhoea but did not require discontinuation of the treatment. Only one dog (in group A) relapsed nine days after treatment discontinuation.

CLINICAL SIGNIFICANCE

Once-daily cephalexin is as effective as twice-daily cephalexin in the treatment of canine superficial pyoderma.

Serum progesterone at human chorionic gonadotropin injection significantly correlate with female age

AIM

In in vitro fertilization-embryo transfer (IVF-ET) higher age and low responses are associated with accelerated luteinization of mature follicles rather than diminished responsiveness. The aim of this study was to determine whether an elevated serum progesterone (P) on the day of human chorionic gonadotropin (hCG) administration during gonadotropin stimulation for IVF-ET is associated with age.

METHODS

E2 (17beta estradiol) and P concentrations on the day of hCG administration, number and quality of oocytes and embryos, and clinical pregnancies were retrospectively analyzed in 460 women undergoing IVF-ET. We evaluated patients according to age; the 25-30 age group (n=140), the 31-35 age group (n=100), the 36-40 (n=90), and the 41-45 age group (n=130).

RESULTS

In the 25-30 age group (n=140) P was 0.67+/-0.3 ng/mL, in the 31-35 age group (n=100) P was 0.87+/-0.2 ng/mL, in the 36-40 age group (n=90) P was 0.95+/-0.2 ng/mL, in the 41-45 age group (n=130) P was 1+/-0.2 ng/mL. The difference between the 25-30 age group and the 41-45 age group was statistically significant (P<0.05).

CONCLUSIONS

Periovulatory levels of serum P vary according to ovarian response to controlled ovarian hyperstimulation. Periovulatory P may reflect inadequate steroidogenesis. In women stimulated with recombinant follicle stimulating hormone for IVF, the serum P on the day of hCG administration increases with age.

Protective effect of SV-IV on platelet-activating factor-induced hypotension, bronchoconstriction and gastric mucosal injury

The inhibitory effect of one of the major proteins secreted by the rat seminal vesicles (SV-IV) on platelet-activating factor (PAF)-induced biological activities was investigated in vivo. SV-IV was found to prevent dose dependently both hypotension and acute bronchospasm caused by PAF administration in guinea-pigs. In addition, SV-IV inhibited both PAF- and ethanol-induced gastric mucosal injury in a dose-dependent manner.

Involvement of NK receptors and beta-adrenoceptors in nitric oxide-dependent relaxation of rabbit aorta rings following electrical-field stimulation

Electrical-field stimulation caused an endothelium-dependent relaxation in rabbit aorta rings precontracted by phenylephrine. The relaxation was reduced in a dose-dependent manner by morphine, benzalkonium, [D-Pro2,D-Trp7,9]substance P and an beta-adrenoceptor antagonist, propranolol. The vasodilatation was enhanced by superoxide dismutase and abolished by haemoglobin and NG-monomethyl-L-arginine. The inhibitory effect of NG-monomethyl-L-arginine was reversed by L-arginine, the precursor of nitric oxide biosynthesis, but not by its enantiomer, D-arginine. These data show that the electrically induced relaxation is independent on nitric oxide released by NK receptors and beta-receptors. Moreover, morphine, by reducing substance P release, decreased the magnitude of electrically induced relaxation, suggesting an indirect role of opioids in the regulation of the peripheral circulation through the control of nitric oxide release. Furthermore our observations confirm the hypothesis that subtypes of beta-adrenoceptors releasing nitric oxide participate in the regulation of vascular tone.

Biological activities of a major protein secreted from the rat seminal vesicles after structural modification catalyzed by transglutaminase in vitro

The immunosuppressive, anti-inflammatory and anti-thrombotic properties of SV-IV, a major protein secreted from the epithelium of rat seminal vesicles, were investigated after transglutaminase-catalyzed covalent incorporation of two molecules of spermidine (Spd) into the protein at the level of Gln-9 and Gln-86. The modified molecular form of the protein (Spd2-SV-IV) showed a more marked inhibitory activity on Con A-induced lymphocyte blastogenesis in comparison with the native protein, whereas no differences in the ability to inhibit the mixed lymphocyte reaction and to decrease the rat epididymal sperm immunogenicity were found between modified and native SV-IV. Spd2-SV-IV was also less effective than native SV-IV to inhibit platelet aggregation induced in vivo by different thrombogenic agents. In contrast, superimposable inhibitory tracings were observed in the in vitro platelet aggregation experiments performed with the two different molecular forms on the protein. Finally, Spd2-SV-IV was shown to retain unchanged the anti-inflammatory activity of native SV-IV.

Endogenous nitric oxide modulates morphine-induced changes in locomotion and food intake in mice

Opioids increase the dopaminergic turnover in nucleus striatum and nucleus accumbens of mice, causing behavioural changes such as increased locomotion and food intake. We have now shown that L-arginine administration increases morphine-induced locomotion and changes in food intake in mice. D-Arginine had no effect, suggesting a stereospecific mechanism. Furthermore NG-nitro-L-arginine methyl ester, a specific inhibitor of nitric oxide synthase, reduced the morphine-induced effects. These results suggest that endogenous nitric oxide could play a role in the modulation of dopaminergic effects elicited by morphine.

Dexamethasone modifies morphine-, atropine-, verapamil-induced constipation in mice

1. The effect of dexamethasone in gastrointestinal constipation induced by morphine, verapamil and atropine in mice has been studied. 2. These drugs caused a dose-related inhibition of charcoal meal transit, which was reversed by dexamethasone. 3. Dexamethasone resulted more active in reversing morphine and atropine constipation, than in modifying verapamil effect. 4. The authors concluded that the interaction of dexamethasone on its receptor could release a larger amount of acetylcholine resulting in a reversion of atropine- or morphine-induced constipation. 5. The minor effect of dexamethasone on verapamil-induced constipation suggest a reduced involvement of calcium influx. 6. The above results suggest a role for steroid in gastrointestinal transit and propose a possible mechanism through which dexamethasone could reverse morphine- and atropine-induced constipation.

Adenosine release in morphine-induced hypotension in rats

1. Following intravenous administration of morphine.HCl a reduction in mean arterial blood pressure (MABP) was produced, quaternary morphine analogue was ineffective. 2. Theophylline and 8-phenyltheophylline administration reduced morphine-induced hypotension. 3. A2 adenosine receptor agonist caused an hypotension while A1 adenosine receptor agonist was ineffective. 4. L-NG-Mono-methylarginine administration reduced the hypotensive effect of exogenous A2 agonist while it was ineffective on morphine-induced hypotension. 5. Morphine-induced hypotension was increased by pretreatment with dipyridamole, whereas tetrabenazine abolished it. 6. The present study is consistent with previous reports on the central hypotensive action of morphine and propose a role for adenosine release in morphine-induced hypotension.

Substance P inactivation by transglutaminase in vitro

Gamma(glutamyl5)spermine derivative of substance P (Spm-SP) was synthesized in vitro in the presence of purified guinea pig liver transglutaminase and Ca2+. The spermine adduct of the neuropeptide was purified by HPLC on a reversed-phase column and characterized by fast atom bombardment mass spectrometry. The biological activities of Spm-SP were tested by assaying, in comparison with substance P, its ability to induce both the contractions of smooth muscle in vitro and the edema formation in vivo. Spm-SP was shown not to elicit contractile responses in the isolated rat stomach strip and duodenum and not to antagonize the spasmogenic effect evoked by the native neuropeptide. Furthermore, Spm-SP was unable, when administered into rats by plantar injection, either to provoke an acute inflammatory response in the hind limb or to antagonize the edema formation induced by a concurrent administration of substance P. These results indicate that the introduction of a large size hydrophilic moiety at the glutamine5 level negatively affects the ability of the neuropeptide to bind to its receptor(s), thus supporting the view that the hydrophobic middle portion of substance P plays a key role in receptor recognition.

Effect of RU-38486 on dexamethasone reversal of morphine-induced constipation in mice

1. Morphine and dexamethasone significantly reduce gastrointestinal transit in mice. The degree of reduction was greater for morphine. 2. Dexamethasone pretreatment was found, however, to antagonize morphine-induced constipation. 3. Cycloheximide does not modify the dexamethasone effects. 4. RU-38486 reverses both the inhibitory action of dexamethasone on gastrointestinal transit and its reducing effect on morphine-induced constipation. 5. These results suggest that dexamethasone might act through binding to receptors not linked to DNA-responsive elements.

The action of dexamethasone on electrically-induced contractions of guinea-pig isolated ileum

1. The effect of dexamethasone and its interaction with morphine has been studied on transmurally-stimulated guinea-pig ileum preparation. 2. Dexamethasone dose-dependently depressed the contractions of the ileum; this action has a rapid onset. 3. Naloxone did not reverse the inhibitory effect of dexamethasone. 4. When dexamethasone and morphine were given in combination the maximum reduction observed was equal to the sum of the single effect of two drugs given individually and naloxone antagonized only the inhibition induced by morphine. 5. Proteic synthesis inhibitors did not modify the inhibition induced by dexamethasone. 6. RU-38486, a glucocorticoid antagonist receptor, antagonized completely the inhibitory effect of DXM without affecting the inhibition induced by morphine showing that the effect of dexamethasone occurs by glucocorticoid receptor-mediated processes.

In vivo and in vitro inhibition of platelet aggregation by SV-IV, a major protein secreted from the rat seminal vesicle epithelium

In summary, the present study documents that platelet aggregation triggered by thrombin, ADP, collagen and PAF both in vivo and in vitro, was prevented by SV-IV in a dose-dependent manner. Only platelet aggregation by AA was not affected by the protein, thus suggesting a possible involvement of PLA2 inhibition in the molecular mechanism at the basis of SV-IV anti-thrombotic effect.

Immunosuppressive and anti-inflammatory properties of a major protein secreted from the epithelium of the rat seminal vesicles

The nonspecies specific immunosuppressive and anti-inflammatory properties of a major protein (SV-IV) secreted from the epithelium of rat seminal vesicles (SV) are described. To detect the immunosuppressive effect, peripheral blood lymphocytes (PBL) were pretreated for 2 hr at 37 degrees with SV-IV, and the protein was maintained in the incubation medium during the whole culture time. We obtained evidence that, during preincubation of PBL and SV-IV the protein was transformed by a transglutaminase (TGase) released from PBL into modified low and high molecular weight forms able to bind to PBL surfaces. It is suggested that T lymphocytes are the possible targets of the immunosuppressive effect. SV-IV seems to inhibit only the early phase of the proliferative response of T lymphocytes to mitogens without having any direct effect on the enzymatic system involved in DNA synthesis. Moreover, the protein SV-IV was also shown to possess an anti-inflammatory property due to a block of the arachidonic acid cascade at the level of the enzyme phospholipase A2 (PLA2). The physiological significance of the immunosuppressive and anti-inflammatory properties of SV-IV are discussed in relation to different aspects of the mammalian reproduction.

Isolation and identification of platelet-activating factor in UV-irradiated guinea pig skin

Platelet activating factor (PAF) neutrophils, platelets, macrophages, endothelial cells, and isolated tissue preparations. In the present study, we have isolated and identified PAF in the skin of guinea pigs undergoing irradiation by UV light.

A comparison of the acute inflammatory response in adrenalectomised and sham-operated rats

Carrageenin pleurisy was induced in adrenalectomised (ADX) and sham-operated (SHO) rats. The magnitude and duration of inflammation, as estimated by fluid exudation and cell migration, was greatly increased (approximately doubled) in ADX rats compared with that in their SHO controls. The content of eicosanoids (6-keto-prostaglandin F1 alpha (6-keto-PGF 1 alpha), thromboxane B2 (TXB2), and leukotriene B4 (LTB4] in inflammatory exudates from ADX rats was significantly (2-4 fold) greater than that of their SHO controls. Resident macrophages obtained from ADX rats produced more eicosanoids per cell per unit time when stimulated in vitro with zymosan, than did cells from the SHO controls. Administration of glucocorticoids blocked the inflammatory response and reduced the release of eicosanoids both in vitro and in vivo in both groups of rats. These data are consistent with the notion that physiological amounts of glucocorticoids exert a tonic inhibitory action on phospholipase activity in normal animals and that the increased secretion of these hormones during the inflammatory response serves to check and control the development of inflammation.

Distinct inhibition of membrane-bound and lysosomal phospholipase A2 by glucocorticoid-induced proteins

Anti-inflammatory steroids induce the release in vivo of antiphospholipase proteins (APP) into the peritoneal cavities of rats. APP were partially purified by ion- exchange chromatography. The main anti-phospholipase activity was recovered in two zones of the elution gradient named APP I and APP II; their molecular weight (mol. wt) was determined with molecular sieve chromatography. Two phospholipase A2 (PLA2) activities were identified from rat peritoneal leucocytes, one with a pH optimum at 4.5 (a lysosomal enzyme) and one with pH optimum at 8.5 (a membrane-bound enzyme); the selective secretion of the former was observed when leucocytes were stimulated by phagocytosis. The effect of APP on both enzyme activities was studied on enzyme preparations from resting leucocytes. APP were also added to leucocytes incubated with or without phagocytozable material. After incubation, PLA2 activities were determined both inside the cells and in the culture medium. APP I revealed a mol. wt of 200 k with a small fragment of 15 k and inhibited membrane-bound PLA2; APP II revealed a mol. wt of 40 k and inhibited lysosomal PLA2.

Relationship between the anti-phospholipase and anti-inflammatory effects of glucocorticoid-induced proteins

Glucocorticoid-induced anti-phospholipase proteins were partially purified by using ion-exchange and molecular sieve chromatography. These proteins, as well as dexamethasone itself, inhibited the hind-paw rat oedema induced by carrageenin. This inhibition was reversed by arachidonic acid, Anti-phospholipase proteins as well as hydrocortisone, also reduced the formation of prostaglandin E2 and leukotriene B4 by phagocytosing leucocytes. A specific monoclonal antibody was able to reverse the inhibition of eicosanoid formation. The mechanism of the anti-inflammatory effect of glucocorticoids and anti-phospholipase proteins is discussed in the light of these results.

Glucocorticoids induce the formation and release of anti-inflammatory and anti-phospholipase proteins into the peritoneal cavity of the rat

1 Dexamethasone and hydrocortisone induced the release of anti-phospholipase proteins into the peritoneal cavities of rats. 2 Adrenocorticotrophic hormone (ACTH) also releases these proteins in normal but not in adrenalectomized rats. 3 Peritoneal lavage proteins were separated by ion-exchange and size exclusion chromatography. The anti-phospholipase activity occurred in four separate fractions with the major component having an apparent mol. wt. of 40 k. 4 Column fractions containing these anti-phospholipase proteins had anti-inflammatory effects in the rat carrageenin pleurisy model whereas other fractions were inactive. 5 The proteins appear to be identical to macrocortin and lipomodulin, the 'second messengers' of glucocorticoid hormone action on the arachidonate system.

Macrocortin: a polypeptide causing the anti-phospholipase effect of glucocorticoids

Anti-inflammatory glucocorticoids inhibit prostaglandin (PG) biosynthesis by preventing arachidonic acid release from phospholipids rather than inhibiting the cyclooxygenase. As in other cells, this steroid action depends on receptor occupation and de novo protein/RNA biosynthesis. We have previously shown in guinea pig perfused lungs and rat peritoneal leukocytes that the effect of steroids in PG generation is mediated by an uncharacterized 'second messenger'. Now, we report that this factor (which we have named 'macrocortin') is an intracellular polypeptide whose release and synthesis are stimulated by steroids. Macrocortin derived from rat peritoneal leukocytes is very similar to that released from guinea pig lungs.

Synthesis and anti-inflammatory activity of 4H-1,4-benzothiazines

A new series of 4H-1,4-benzothiazine derivatives have been synthesized. These products were obtained by treatment with SO2Cl2 in dry ether at room temperature of 1,3-benzothiazolines N-acetylated. The 1,3-benzothiazolines were prepared by condensation in benzene of 2-aminothiophenol with several ketones, in the presence of p-toluenesulphonic acid as catalyst. Preliminary pharmacological studies on the anti-inflammatory activity of these compounds are reported.

Hydrocortisone-induced inhibitor of prostaglandin biosynthesis in rat leucocytes

Rat peritoneal luecocytes incubated with hydrocortisone (10 micrograms/ml) release a factor which inhibits prostaglandin generation. The steroid-induced inhibitor, which mediates the anti-phospholipase effect of antiinflammatory steroids, may be a protein or a polypeptide since its formation is blocked by cycloheximide, a known inhibitor of protein synthesis.

Mechanism of inhibition of prostaglandin biosynthesis by hydrocortisone in rat leucocytes

Hydrocortisone (10 microgram/ml) greatly inhibits the prostaglandin release by rat peritoneal leucocytes phagocytosing killed bacteria. The inhibition, which occurs after an initial latency of 30 min, is completely reversed by either actinomycin D (0.5 microgram/ml) or cycloheximide (1 microgram/ml). Since these antibiotics are known inhibitors of DNA-dependent RNA synthesis and protein synthesis respectively, it appears that the mechanism of inhibition of prostaglandin biosynthesis by hydrocortisone in rat leucocytes involves stimulation of transcription and induction of protein synthesis.

Enhancement of carrageenin foot oedema by 1,10 -phenanthroline and evidence for the bradykinin as endogenous mediator

Carrageenin oedema in enhanced by the simultaneous injection in the rat paw of 1,10-phenanthroline, a kininase inhibitor. The analysis of the time-course of this enhancement showed that the maximal effect was observed about 3 hours after the injection. This enhancement was also present when the oedema-producing agent was cellulose sulphate, a kinin-releasing compound. On the contrary, oedema induced by eggwhite as well as by dextran, which are mainly mediated by histamine and 5-hydroxytryptamine, were unaffected by 1,10-phenanthroline. These results further support the role of kinins in the pathogenesis of carrageenin oedema.